Spent Flow Discharge Apparatus for an Instream Fluid Power-Extraction Machine

An instream fluid power-extraction machine to be immersed in an ambient flow of a surrounding fluid so as to capture a portion of the fluid, extract energy from the captured fluid thereby producing spent fluid, and then discharge the spent fluid as discharged fluid back into the ambient flow, wherein said machine comprises:

• a housing that bounds a fluid intake inlet and that includes an ambient flow deflector, wherein said fluid intake inlet is oriented facing in an axial direction to be arranged facing axially forwardly upstream in the ambient flow, said ambient flow deflector extends laterally or radially outwardly to an outer edge of said ambient flow deflector located laterally or radially outwardly from said fluid intake inlet, and said ambient flow deflector is configured and arranged to intercept and deflect laterally or radially outwardly a portion of the ambient flow to form thereof an accelerated flow of the surrounding fluid at said outer edge of said ambient flow deflector;
• a downstream body arranged axially rearwardly from said ambient flow deflector, with a discharge outlet formed between said outer edge of said ambient flow deflector and a forward portion of said downstream body, wherein said downstream body comprises a mixing surface that extends laterally or radially outwardly from said forward portion to a widest part of said downstream body located axially rearwardly from said discharge outlet, and said downstream body further comprises a backflow preventer having a continuous closed imperforate backflow prevention surface that extends from said widest part of said downstream body laterally or radially inwardly to a closed center;
• a fluid flow channel within said machine communicating from said fluid intake inlet to said discharge outlet, wherein said fluid intake inlet is configured and adapted to capture the captured fluid, and said discharge outlet is configured and adapted to discharge the spent fluid as the discharged fluid back into the surrounding fluid;
• and
• a power extraction device arranged in said fluid flow channel, and configured to extract power from the captured fluid flowing in said fluid flow channel thereby producing the spent fluid.